Handheld outdoor power devices such as trimmers, blowers, chainsaws, and/or the like, are often used to perform tasks relating to yard/grounds maintenance or even commercial resource harvesting activities that require them to be mobile. Although there are several options for powering such devices, including combustion engines, corded electric motors, or battery powered electric motors, each option may be viewed as having advantages in certain environments and for certain users.
Some trimming devices employ a trimmer line and are referred to as string trimmers. Alternatively, such devices may be known as edge trimmers, line trimmers, weed whips and/or the like. The trimmer line, which may be a monofilament line, is quite effective at cutting when rotated at high speed. Such a trimmer line is extended and held somewhat rigid by centrifugal forces while being rotated. The trimmer line is wound upon a reel or spool and the trimmer line can be released by bumping the trimmer head on the ground during operation. Historically, a knife is placed at one end of a trim shield of the trimmer to cut the line to an appropriate length as the line swings by the trim shield. The knife and the trim shield are often shaped and positioned in contemplation of a single direction of rotation.